In various kinds of organisms, structures having a linkage of disaccharide of N-acetylgalactosamine-N-acetylglucosamine have been found in oligosaccharides of glycoproteins and glycolipids [see References 1 and 2]. In humans, this disaccharide structure is known as a β1-4 linkage (GalNAcβ1-4GlcNAc), and is found only in N-glycans [see Reference 3]. Methods for obtaining human-type oligosaccharides including said structure are limited to methods using complicated chemical synthesis and methods obtaining the oligosaccharides from natural proteins. Further, the above disaccharide structure includes in vivo a galactose substituted for a N-acetylgalactosamine. Therefore, it is a lengthy, laborious process to obtain oligosaccharides having the target disaccharide structure.
Prior to the present application, the inventors identified ppGalNAc-T10, -T11, -T12, -T13, -T14, -T15, -T16, -T17, CSGalNAc-T1, and -T2 as enzymes having an activity of transferring N-acetylgalactosamine to glucuronic acids and polypeptides, and further, they clarified the structures of these genes. Already known are at least 22 N-acetylgalactosamine transferases that have the activity of transferring N-acetylgalactosamine (Table 1), and each of the transferases have different specificities of acceptor substrates.
TABLE 1N-acetylgalactosamine transferase and the substrate specificitySubstrateFormal NameAbbreviationOriginspecificityReferencesUDP-GalNAc:polypeptideppGalNAc-T1humanSer/ThrWhite, T. etc (1995)N-acetylgalactosaminyltransferase IUDP-GalNAc:polypeptideppGalNAc-T2humanSer/ThrWhite, T. etc (1995)N-acetylgalactosaminyltransferase IIUDP-GalNAc:polypeptideppGalNAc-T3humanSer/ThrBennet, E. P. etc (1996)N-acetylgalactosaminyltransferase IIIUDP-GalNAc:polypeptideppGalNAc-T4humanSer/ThrBennet, E. P. etc (1998)N-acetylgalactosaminyltransferase IVUDP-GalNAc:polypeptideppGalNAc-T6humanSer/ThrBennet, E. P. etc (1999) (1)N-acetylgalactosaminyltransferase VIUDP-GalNAc:polypeptideppGalNAc-T7humanSer/ThrBennet, E. P. etc (1999) (2)N-acetylgalactosaminyltransferase VIIUDP-GalNAc:polypeptideppGalNAc-T8humanSer/ThrWhite, K. E. etc (2000)N-acetylgalactosaminyltransferase VIIIUDP-GalNAc:polypeptideppGalNAc-T9humanSer/ThrToba, S. etc (2000)N-acetylgalactosaminyltransferase IXUDP-GalNAc:polypeptideppGalNAc-T10humanSer/ThrJP No. 2001-401455 (unpublished)N-acetylgalactosaminyltransferase XUDP-GalNAc:polypeptideppGalNAc-T11humanSer/ThrJP No. 2001-401507 (unpublished)N-acetylgalactosaminyltransferase XIUDP-GalNAc:polypeptideppGalNAc-T12humanSer/ThrJP No. 2001-401507 (unpublished)N-acetylgalactosaminyltransferase XIIUDP-GalNAc:polypeptideppGalNAc-T13humanSer/ThrJP No. 2001-401507 (unpublished)N-acetylgalactosaminyltransferase XIIIUDP-GalNAc:polypeptideppGalNAc-T14humanSer/ThrGuo, J. M. etc (2002)N-acetylgalactosaminyltransferase XIVUDP-GalNAc:polypeptideppGalNAc-T15humanSer/ThrJP No. 2001-401507 (unpublished)N-acetylgalactosaminyltransferase XVUDP-GalNAc:polypeptideppGalNAc-T16humanSer/ThrJP No. 2001-401507 (unpublished)N-acetylgalactosaminyltransferase XVIUDP-GalNAc:polypeptideppGalNAc-T17humanSer/ThrJP No. 2001-401507 (unpublished)K-acetylgalactosaminyltransferase XVIIβ1,4-N-acetylgalactosamineβ4GalNAcThumanGM3, GD3, LacCerNagata, Y. etc (1992)transferaseUDP-GalNAc:H-α1,3-N-Hist blood AhumanFucα1,2Galβ1-RYamamoto, F. etc (1990)acetylgalactosaminegrouptransferasetransferaseUDP-GalNAc:globosideformalinhumanGalNAcβ1-3Galα1-Xu, H. etc (1999)α1,3-N-acetylgalactosamineglycolipid4Galβ1-3Glc-Certransferase IsynthaseChondroitin sulfateCSGalNAc-T1humanGlcAJP No. 2002-129156 (unpublished)N-acetylglactosamintransferase IChondroitin sulfateCSGalNAc-T2humanGlcAJP No. 2002-24202 (unpublished)N-acetylglactosamintransferase II